What are the symptoms and manifestations of vagus nerve excitation?
Nov 27, 2024
Source: Cainiu Health
Dr. Lv Zhiqin
Introduction
Vagus nerve excitation typically presents with symptoms such as bradycardia, decreased blood pressure, nausea and vomiting, slowed respiration, and dilated pupils. The vagus nerve has an inhibitory effect on the heart; when it becomes excessively excited, it may cause a significant decrease in heart rate, falling below the normal range, known as bradycardia. This phenomenon can also occur naturally in some healthy individuals, such as during deep breathing or the diving reflex.
Vagal nerve excitement generally presents with symptoms such as bradycardia, decreased blood pressure, nausea and vomiting, slowed respiration, and dilated pupils. Detailed analysis is as follows:
1. Bradycardia: The vagus nerve exerts an inhibitory effect on the heart. When it becomes excessively excited, it may cause the heart rate to drop below the normal range, resulting in bradycardia. This phenomenon can also occur naturally in some healthy individuals, such as during deep breathing or the diving reflex.
2. Decreased Blood Pressure: Vagal nerve excitement can also affect vascular tone, causing vasodilation and subsequently lowering blood pressure. This drop in blood pressure may lead to symptoms such as dizziness or fainting.
3. Nausea and Vomiting: Excitement of the vagus nerve can cause contractions of gastrointestinal smooth muscle and increased gastric acid secretion, resulting in nausea. This may be accompanied by abdominal discomfort or pain. Frequent vomiting can lead to complications such as dehydration and electrolyte imbalance.
4. Slowed Respiration: Excitation of the vagus nerve causes slower breathing with increased depth, which helps improve gas exchange.
5. Dilated Pupils: The vagus nerve regulates pupil size through the sympathetic nervous system. When it is excited, sympathetic nerve activity is suppressed, leading to pupil dilation. Pupil dilation may be a sign of central nervous system disorders, such as increased intracranial pressure or drug poisoning.
If any discomfort symptoms occur, it is recommended to seek medical attention at a hospital promptly and follow medical advice for treatment.
